Modular multi-articulated patient support system

ABSTRACT

A surgical table for supporting a patient during a surgical procedure and including a patient support structure, a first support structure, and a second support structure. The patient support structure is configured to support the patient during the surgical procedure and may be operably coupled at a first end to the first support structure and at a second end to the second support structure. The first support structure includes a first column and a first displacement apparatus operably coupling the first column to the first end of the patient support structure.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/616,500, filed Feb. 6, 2015, which application is a continuation ofU.S. patent application Ser. No. 13/902,536, filed May 24, 2013, nowU.S. Pat. No. 8,978,180, which application is a continuation-in-part ofU.S. patent application Ser. No. 13/317,012 filed Oct. 6, 2011, now U.S.Pat. No. 8,719,979 entitled “Patient Positioning Support Structure,”which application is a continuation of U.S. patent application Ser. No.12/460,702, filed Jul. 23, 2009, now U.S. Pat. No. 8,060,960, which is acontinuation of U.S. patent application Ser. No. 11/788,513, filed Apr.20, 2007, now U.S. Pat. No. 7,565,708, which claims the benefit of U.S.Provisional Application No. 60/798,288 filed May 5, 2006 and is also acontinuation-in-part of U.S. patent application Ser. No. 11/159,494filed Jun. 23, 2005, now U.S. Pat. No. 7,343,635, which is acontinuation-in-part of U.S. patent application Ser. No. 11/062,775filed Feb. 22, 2005, now U.S. Pat. No. 7,152,261. The disclosures of allthe preceding applications and patents are incorporated by referenceherein in their entireties.

FIELD OF THE INVENTION

The present invention is broadly concerned with a system for positioningand supporting a patient during examination and treatment, includingmedical procedures such as imaging, surgery and the like. Moreparticularly, it is concerned with a system having patient supportmodules that can be independently adjusted for selective positioning ofportions of the patient's body by movement up and down, tilting,pivoting, angulating or bending of the trunk in a supine, prone orlateral position, multi-axial motion of joints, rotation of the patientabout an axis from a prone to a lateral to a supine position, and thatis suitable for integrated computer software actuation.

BACKGROUND OF THE INVENTION

Modern surgical practice incorporates imaging techniques andtechnologies throughout the course of patient examination, diagnosis andtreatment. For example, minimally invasive surgical techniques, such aspercutaneous insertion of spinal implants, involve small incisions thatare guided by continuous or repeated intraoperative imaging. Theseimages can be processed using computer software programs that producethree dimensional images for reference by the surgeon during the courseof the procedure. If the patient support surface is not radiolucent orcompatible with the imaging technologies, it may be necessary tointerrupt the surgery periodically in order to remove the patient to aseparate surface for imaging followed by transfer back to the operatingsupport surface for resumption of the surgical procedure. Such patienttransfers for imaging purposes may be avoided by employing radiolucentand other imaging compatible systems. The patient support system shouldalso be constructed to permit unobstructed movement of the imagingequipment and other surgical equipment around, over and under thepatient throughout the course of the surgical procedure withoutcontamination of the sterile field.

It is also necessary that the patient support system be constructed toprovide optimum access to the surgical field by the surgery team. Someprocedures require positioning of portions of the patient's body indifferent ways at different times during the procedure. Some procedures,for example, spinal surgery, involve access through more than onesurgical site or field. Since all of these fields may not be in the sameplane or anatomical location, the patient support surfaces should beadjustable and capable of providing support in different planes fordifferent parts of the patient's body as well as different positions oralignments for a given part of the body. Preferably, the support surfaceshould be adjustable to provide support in separate planes and indifferent alignments for the head and upper trunk portion of thepatient's body, the lower trunk and pelvic portion of the body as wellas each of the limbs independently.

Certain types of surgery, such as orthopedic surgery, may require thatthe patient or a part of the patient be repositioned during theprocedure while in some cases maintaining the sterile field. Wheresurgery is directed toward motion preservation procedures, such as byinstallation of artificial joints, spinal ligaments and total discprostheses, for example, the surgeon must be able to manipulate certainjoints while supporting selected portions of the patient's body duringsurgery in order to facilitate the procedure. It is also desirable to beable to test the range of motion of the surgically repaired orstabilized joint and to observe the gliding movement of thereconstructed articulating prosthetic surfaces or the tension ofartificial ligaments before the wound is closed. Such manipulation canbe used, for example, to verify the correct positioning and function ofan implanted prosthetic disc or joint replacement during a surgicalprocedure. Where manipulation discloses binding, suboptimal position oreven crushing of the adjacent vertebrae, for example, as may occur withosteoporosis, the prosthesis can be removed and the adjacent vertebraefused while the patient remains anesthetized. Injury which mightotherwise have resulted from a “trial” use of the implantpost-operatively will be avoided, along with the need for a second roundof anesthesia and surgery to remove the implant or prosthesis andperform the revision, fusion or corrective surgery.

There is also a need for a patient support surface that can be rotated,articulated and angulated so that the patient can be moved from a proneto a supine position or from a prone to a 90° position and wherebyintra-operative extension and flexion of at least a portion of thespinal column can be achieved. The patient support surface must also becapable of easy, selective adjustment without necessitating removal ofthe patient or causing substantial interruption of the procedure.

For certain types of surgical procedures, for example spinal surgeries,it may be desirable to position the patient for sequential anterior andposterior procedures. The patient support surface should also be capableof rotation about an axis in order to provide correct positioning of thepatient and optimum accessibility for the surgeon as well as imagingequipment during such sequential procedures.

Orthopedic procedures may also require the use of traction equipmentsuch as cables, tongs, pulleys and weights. The patient support systemmust include structure for anchoring such equipment and it must provideadequate support to withstand unequal forces generated by tractionagainst such equipment.

Articulated robotic arms are increasingly employed to perform surgicaltechniques. These units are generally designed to move short distancesand to perform very precise work. Reliance on the patient supportstructure to perform any necessary gross movement of the patient can bebeneficial, especially if the movements are synchronized or coordinated.Such units require a surgical support surface capable of smoothlyperforming the multi-directional movements which would otherwise beperformed by trained medical personnel. There is thus a need in thisapplication as well for integration between the robotics technology andthe patient positioning technology.

While conventional operating tables generally include structure thatpermits tilting or rotation of a patient support surface about alongitudinal axis, previous surgical support devices have attempted toaddress the need for access by providing a cantilevered patient supportsurface on one end. Such designs typically employ either a massive baseto counterbalance the extended support member or a large overhead framestructure to provide support from above. The enlarged base membersassociated with such cantilever designs are problematic in that they mayobstruct the movement of C-arm mobile fluoroscopic imaging devices.Surgical tables with overhead frame structures are bulky and may requirethe use of dedicated operating rooms, since in some cases they cannot bemoved easily out of the way. Neither of these designs is easily portableor storable.

Thus, there remains a need for a patient support system that provideseasy access for personnel and equipment, that can be easily and quicklypositioned and repositioned in multiple planes without the use ofmassive counterbalancing support structure, and that does not requireuse of a dedicated operating room.

BRIEF SUMMARY OF THE INVENTION

Aspect of the present disclosure involve a modular multi-articulatedpatient support system that permits adjustable positioning,repositioning and selectively lockable support of a patient's head andupper body, lower body and limbs in multiple individual planes whilepermitting tilting, rotation angulation or bending and othermanipulations as well as full and free access to the patient by medicalpersonnel and equipment. The system of the invention includes a pair ofindependently height-adjustable upright end support columns connected toa horizontally length-adjustable base. The support columns are coupledwith respective horizontal support assemblies, which include rotation,angulation and separation adjustment structure. The horizontal supportassemblies are pivotally connected to a patient support structure whichmay be raised, lowered and rotated about a longitudinal axis in eitherhorizontal or tilted orientation.

In certain implementations, the patient support structure is articulatedand includes a body board rotatably coupled with a pair of leg boards.The leg boards are each disengageable at the outboard ends, and havemulti-directional movement which can be locked in place. A drop downcenter support is shiftable to engage the base when the outboard ends ofthe leg boards are disengaged from the support column.

In certain implementations, the patient support structure may also beconfigured to include two pairs of opposed patient supports which can beconstructed as frames or boards that are, attached in spaced relation atthe outboard ends to a corresponding upright end support column. Acoordinated drive system raises, lowers, tilts and rotates the supports,which may be positioned in overlapping relation when the base isadjusted to a shortened, retracted position. When in an alignedposition, the pairs of patient supports may be rotated in unison about alongitudinal axis to achieve 180° repositioning of a patient, from aprone to a supine position.

Aspects of the present disclosure also involve a surgical table forsupporting a patient during a surgical procedure. The surgical tableincludes a patient support structure, a first support structure, and asecond support structure.

In certain implementations, the patient support structure may beconfigured to support the patient during the surgical procedure and maybe operably coupled at a first end to the first support structure and ata second end to the second support structure.

In certain implementations, the first support structure includes a firstcolumn and a first displacement apparatus operably coupling the firstcolumn to the first end of the patient support structure. The firstdisplacement apparatus may include a first rotation assembly operablycoupled between the first column and the first end of the patientsupport structure. The first rotation assembly may be configured torotate the patient support structure relative to the first column andrelative to a rotation axis that is parallel to and positioned above alongitudinal axis of the patient support structure.

In certain implementations, the second support structure may include asecond column operably coupled to the second end of the patient supportstructure and a second displacement apparatus operably coupling thesecond column to the second end of the patient support structure. Thesecond displacement apparatus may include a second rotation assemblyoperably coupled between the second column and the second end of thepatient support structure. The second rotation assembly may beconfigured to rotate the patient support structure relative to secondvertical column and relative to the rotation axis.

In certain implementations, the patient support structure includes afirst segment including the first end, a second segment including thesecond end and opposite the first segment, and an inward articulationbetween inner ends of the first and second segments about which thefirst and second segments articulate relative to each other.

In certain implementations, the first displacement apparatus furtherincludes a first angulation assembly operably coupled between the firstcolumn and the first end of the patient support, the first angulationassembly configured to angle the first segment of the patient supportstructure relative to the first column. The first angulation assemblymay include a first member and a second member. The second member may beoperably coupled to the first column via a first pivot; and the secondmember may be operably coupled to the first end of the first segment ofthe patient support structure and pivotally coupled to the first membervia a second pivot.

In certain implementations, the first angulation assembly furtherincludes a third pivot near an intersection between the first end of thefirst segment of the patient support and the second member.

In certain implementations, the second displacement apparatus furtherincludes a second angulation assembly operably coupled between thesecond column and the second end of the second segment of the patientsupport structure, the second angulation assembly configured to anglethe second segment of the patient support structure relative to thesecond column. The second angulation assembly may include a third memberoperably coupled to the second column via a third pivot and a fourthmember operably coupled to the second end of the second segment of thepatient support structure and pivotally coupled to the third member viaa fourth pivot.

In certain implementations, the rotation axis is parallel to andpositioned above the longitudinal axis of the patient support structurewhen the patient support structure supports the patient from below.

In certain implementations, the inward articulation comprises a jointabout which the inner ends of the first and second segments are coupled.

In certain implementations, the joint is a ball and socket jointassembly.

Various objects and advantages of this invention will become apparentfrom the following description taken in relation to the accompanyingdrawings wherein are set forth, by way of illustration and example,certain embodiments of this invention.

The drawings constitute a part of this specification, include exemplaryembodiments of the present invention, and illustrate various objects andfeatures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side perspective view of a modular multi-articulated patientsupport system in accordance with the present invention.

FIG. 2 is a top plan view of the system with parts of the motor housingbroken away to show the motor and drive shaft.

FIG. 3 is a side elevational view of the system.

FIG. 4 is a side elevational view similar to that shown in FIG. 3, withthe pillow support structure disengaged from the bracket and pivoted 90°to form an upright brace.

FIG. 5 is a side perspective view of the system showing a patientpositioned on the support surfaces in a generally supine position withthe leg supports disengaged at the foot end and equipped with tractionboots, and showing one of the leg supports pivoted and lowered forabduction of the patient's right leg and to achieve hyperextension ofthe hip.

FIG. 6 is a side elevational view of the system similar to that shown inFIG. 5, with the second support column and associated base rail removed,and the patient's head and feet lowered to leave the hip area elevatedfor disarticulation, such as is needed for minimally invasive total hipreplacement.

FIG. 7 is a perspective end view of the system with an optional upperpatient support structure installed and with the motor and drive shaftshown in phantom.

FIG. 8 is an enlarged detail of the rotation and angulationsubassemblies, with parts of the housing omitted to show details of thegears.

FIG. 9 is a side elevational view of one end of the system, with partsof the rotation and angulation subassemblies shown in section.

FIG. 10 is a greatly enlarged detail of the structures shown in FIG. 9.

FIG. 11 is a greatly enlarged detail similar to that shown in FIG. 10,with the patient support structure angled upwardly.

FIG. 12 is a greatly enlarged detail similar to that shown in FIG. 10,with the patient support structure angled downwardly.

FIG. 13 is a view of a ball joint housing as viewed from the foot end,and showing a pair of set screws, with a portion of the housing brokenaway to show engagement of a set screw with the ball.

FIG. 14 is an exemplary perspective view of a ball joint engaged by oneof the set screws.

FIG. 15 is an enlarged side perspective detail view of the ball andsocket assembly shown in FIGS. 1 and 3, with the ball shown in phantom.

FIG. 16 is an enlarged perspective detail view of the ball and socketassembly depicted in FIGS. 1 and 3.

FIG. 17 is an exploded perspective view of the ball and socket assemblyshown in FIG. 16.

FIG. 18 is a side perspective view of an alternate modularmulti-articulated patient support system having a first pair of patientsupport structures, with a second pair of support structures shown inphantom.

FIG. 19 is a side perspective view of the system shown in FIG. 18showing the patient support structures rotated 180° and with the firstset of patient support structures in a raised position, a patient shownin phantom in a supine position and secured to the second set of patientsupport structures.

FIG. 20 is a side perspective view similar to that of FIG. 19 with thefirst set of patient support structures in a lowered, positionapproaching contact with a patient.

FIG. 21 is a side perspective view similar to FIG. 20, with the firstset of patient support structures fully lowered to a patient-contactingposition, and the structures and patient rotated approximately 30°.

FIG. 22 is a side perspective view of the system following 180°rotation, with the patient in a prone position and the second set ofpatient support structures removed.

FIG. 23 is a side perspective view similar to FIG. 22, with first columnlowered to place the patient in Trendelenburg's position.

FIG. 24 is a side perspective view of the system showing a patient in alateral position on two centrally raised support surfaces, with anoptional leg spar and patient arm transfer board shown in phantom.

FIG. 25 is a side elevation of the system with both first and secondpairs of support structures in place and showing in phantom the foot endcolumn and associated patient support structures shifted toward the headend.

FIG. 26 is a side elevation of the system with the head end patientsupport structures in an elevated position and the foot end patientsupport structures in a lowered position supporting a patient in a90°/90° kneeling prone position.

FIG. 27 is a side elevation similar to FIG. 26, with the first columnraised, the second column lowered and the associated head and foot endpatient support structures pivoted and supporting a patient in a 90°/90°kneeling prone position approximately 30° from horizontal.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention, which may be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present invention in virtually anyappropriately detailed structure.

Referring now to the drawings, a modular patient support system inaccordance with the invention is generally designated by the referencenumeral 1 and is depicted in FIGS. 1-17. The system 1 broadly includesan elongate length-adjustable base 2 surmounted at either end byrespective first and second upright support piers or columns 3 and 4which are connected to respective first and second horizontal supportassemblies 5 and 6. Between them, the support assemblies 5 and 6 upholdan elongated patient support structure 10 and optionally, a removablesecond patient support structure 10 a (FIG. 8).

When viewed from above, the base 2, has an approximately I-shapedconfiguration, including first and second low stabilizing plinths orfeet 11 and 12 adjustably interconnected by a base rail or crossbar 13.The crossbar 13 includes an expansion mechanism of first and secondtelescoping rail sections 14 and 15. The first rail section 14 issubstantially hollow and sized for reception of the retracting secondrail section 15. The crossbar 13 may be selectively elongated andshortened as needed when a portion of the length of the second rail 15is slidingly and telescopically received within the first rail 14. Thecrossbar 13 also includes a locking assembly 20 (FIG. 3), which mayinclude a releasable rack 21 positioned on the inner surface of thefirst rail 14, and a pinion gear 22 coupled with the end of the secondrail 15, or any other suitable structure enabling extension, retractionand selective locking of the crossbar 13. The horizontal telescopingaction of the crossbar 13 and engagement/disengagement of the lockingassembly 20 may be actuated by a motor 23 housed within the foot 11 or12.

As best shown in FIGS. 3 and 4, the system is optionally equipped with acarriage assembly consisting of a series of spaced apart casters orwheels 24 extending below the feet 11 and 12 and center portion of thefirst rail 14. The wheels 24 associated with the feet 11 and 12 are eachequipped with a floorlock foot lever 25 that operates to disengage thewheels and lower the foot 11 or 12 into a floor-engaging position. Inthis lowered position the combined weight of the base 2 and respectiveupright support column 3 or 4 serves as a brake against inadvertentshifting of the system 2.

The first and second feet 11 and 12 are surmounted by respective firstand second upright end supports or columns 3 and 4. These columns eachinclude a plurality of telescoping lift arm segments 3 a, 3 b and 3 c or4 a, 4 b and 4 c which permit the height of each of the columns 3 and 4to be selectively increased and decreased in order to raise and lowerthe attached patient support structure 10. It is foreseen that the base2 and vertical supports 3 and 4 may be constructed so that the firstfoot 11 and support column 3 have substantially greater mass than thesecond foot 12 and support column 4 or vice versa in order toaccommodate the uneven weight distribution of the human body. Suchreduction in size at the foot end of the system 1 may be employed insome embodiments to facilitate the approach of personnel and equipment,for example, when a patient is positioned in a lithotomy position.

Each of the horizontal support assemblies 5 and 6 includes a rotationsubassembly 26 and angulation subassembly 27 which are interconnected bya separation subassembly 28 and associated circuitry linked to acontroller 29 (FIG. 1) for cooperative and integrated actuation andoperation. The rotational subassembly 26 enables coordinated rotation ofthe patient support structure 10 about a longitudinal axis. Theangulation subassembly 27 enables independent angular adjustment of eachend of the patient support structure 10 and selective tilting of thelongitudinal axis. The separation subassembly 28 enables each end of thepatient support structure 10 to be raised and lowered with respect to anoptional second patient support structure 10 a mounted in spacedrelation to the rotation subassembly.

The rotation subassembly or mechanism 26 is shown in FIGS. 2 and 7-10 toinclude first and second motor housings 30 and 31 surmounting respectivesupport columns 3 and 4. A main rotational shaft 32 extends from eachmotor housing 30 and 31 and turns one of a pair of correspondingrotatable blocks 33, each of which is connected to an angulationsubassembly 27 by means of a separation subassembly 28.

Each housing 30 or 31 contains a rotary electric motor or other actuator34 drivingly engaged with a transverse drive shaft 35 supported at theforward end by an apertured bearing wall 40 (FIGS. 2 and 7). The driveshaft 35 includes a drive gear 41 that in turn engages a gear 36 at theend of the main rotational shaft 32. The main shaft 32 is tapered orstepped down toward the gear 36 and includes a radially expandedmounting flange or collar 42 in spaced relation to the inboard end(FIGS. 8-12). The shaft 32 is fitted with a pair of tapered rollerbearings 43 that engage the inner surface of the motor housing 30 or 31.An inboard end portion of each main shaft 32 projects outside the motorhousing 30 or 31 for connection with the rotatable block 33. As shown inFIGS. 2 and 9-12, the rotatable block 33 is apertured to receive theinboard end of the main shaft 32, which is fastened in place with boltsor the like through the apertured collar 42 and onto the rear surface ofthe block 33. The main shaft 32 is bored through to include a horizontalbore or channel 44 that extends along its length and the rotatable block33 includes a corresponding bore or channel 45. The channels are locatedso that, when the shaft 32 is installed in the rotatable block 33, thechannels 44 and 45 are collinear. The housing 30 includes acorresponding aperture that is normally covered by an escutcheon, coveror cap 46. The cap 46 may be removed to open a continuous passagewayfrom the outboard surface of the housing 30 to the inboard surface ofthe rotatable block 33. Cables may be passed or threaded through thispassageway for use in conjunction with for example, a traction harnessor other skeletal traction apparatus (not shown).

As shown in FIGS. 1, 2 and 5, the normally uppermost surface of eachrotatable block 33 includes a pair of spaced apertures or slide channels47 that are sized for receiving a pair of removable elongate riser posts48 (FIG. 8) for supporting an optional second patient support structure10 a. The riser posts 48 are depicted as having a generally tubularconfiguration, and each includes a series of vertically spaced apertures49 for receiving pins 49 a for securing the second patient supportstructure 10 a in place at a preselected height in spaced relation tothe first patient support structure 10.

The rotation mechanism 26 is operated by actuating the motor 34 using aswitch or other similar means. The motor 34 operates to turn or rotatethe transverse drive shaft 35 and associated drive gear 41, whichengages the gear 36 on the main shaft 32, causing the main shaft 32 toturn or rotate about a longitudinal axis A of the system 10 (FIGS. 1, 2,7 and 10). The collar 42 of the rotating main shaft 32 is in fixedengagement with and serves to turn or rotate the rotatable block 33. Therotatable block 33 is remotely coupled with and turns or rotates theassociated patient support structure 10 via the angulation andseparation subassemblies 27 and 28 and the patient support structure 10a via the riser posts 48, to be more fully described hereinafter.

The angulation subassembly or pivotal mount 27 is coupled with thepatient support structure 10 for enabling selective angular adjustmentof the support structure 10. As best shown in FIGS. 8-12, eachangulation subassembly 27 includes a gear box 50 that houses a pivotablenut pivot block 51 that is intercoupled with a pivotable bracket arm 52that supports a table top or other patient support structure 10 inaccordance with a preselected, adjustable angular orientation or pitch.The inboard wall of the gear box 50 is apertured to receive the bracketarm 52, and the outboard aspect is substantially open to permit easyaccess for maintenance. The floor of the gear box 50 is apertured orpunched out to accommodate upwardly projecting attachments to agenerally rectangular mounting plate or motor housing mount 53 that ispivotally mounted below the floor of the gear box 50 as well as a drivemechanism for the separation subassembly 28 to be more fully described.Pivot pins or trunnions (not shown) project from the opposite ends ofthe motor housing mount 53 and are aligned to define a pivot axis thatis orthogonal to a longitudinal axis of the system 1. Each trunnion,along with a corresponding bushing, is received in a respective flangedpillow block bearing 54 (FIG. 8) that is fastened to the under surfaceof the gear box 50. The trunnions enable the motor housing mount 53 totip or rock slightly to and fro about the pivot axis in response tostresses on the attachments it supports.

As shown in FIG. 8, the motor housing mount 53 has a pair of spaced,side-by-side apertures through the planar surface thereof torespectively receive a DC motor or other suitable actuator 55 within ahousing, and a jack or lead screw 56. The motor 55 includes a driveshaft that extends downwardly to engage a motor pulley (not shown). Astepped down lower portion of the lead screw 56 is received within abearing housing 60 that is fastened to the lower surface of the motorhousing mount 53 from below (FIGS. 11-12). The bearing housing 60contains a pair of angular contact bearings 61 for engagement with thelead screw 56. A further stepped down portion of the lead screw extendsdownwardly below the bearing housing 60 to engage a pulley 62 driven bya belt 63 that is reeved about the motor pulley. The parts extendingbelow the motor housing mount 53 are covered by a generally rectangularpan or belt housing 64 and the open outboard wall of the gear box 50 iscovered by a gear box cover plate 65 (FIG. 10), each held in place by aplurality of fasteners such as panhead screws.

The upper end of the lead screw 56 extends through a clearance slot oraperture in the bracket arm 52 and then through the nut pivot block 51which is fixedly secured to a lead nut 70. The lead screw 56 is threadedinto the lead nut 70. The nut pivot block 51 includes a pair ofprojecting pivot pins or trunnions (not shown), which are aligned todefine a pivot axis orthogonal to a longitudinal axis of the system 1.Each trunnion is received along with a corresponding bushing in arespective flanged pillow block bearing 71 that is fastened by bolts orthe like into the upper rearward surface of the bracket arm 52 (FIG. 8).This structure enables the nut pivot block 51 and attached lead nut 70to tip or rock to and fro to accommodate slight changes in the angularorientation or pitch of the lead screw 56.

The bracket arm 52 has a generally dog-leg configuration and includes anelongate clearance slot 72 positioned lengthwise adjacent the outboardend for receiving the upper portion of the lead screw 56. The lateralsurface of the shank of the bracket arm 52 adjacent its inboard endincludes a pair of opposed projecting pivot pins or trunnions 73 alignedto define a pivot axis orthogonal to a longitudinal axis of the system1. Each trunnion 73 is received along with a corresponding bushing in arespective flanged block bearing 74. The bearings are mounted by meansof fasteners in partially inset or recessed fashion in correspondinggrooves or depressions formed on the inboard surface of the gear box 50.

The distance between the pivot axis defined by the bracket arm trunnions73 and the pivot axis defined by the trunnions of the motor housingmount 53 is fixed. The distance between the pivot axis of the nut pivotblock 51 and the bracket arm pivot axis 73 is also fixed. Thus,alteration of the distance between the nut pivot block 51 and the motorhousing mount 53 causes the bracket arm 52 to ride up or down on thelead screw 56. The clearance slot 72 in combination with the pivotingaction of the nut block 51 and the motor housing mount 53 accommodatesthe tilted aspect of the lead screw 56 and permits the outboard end ofthe bracket arm to ride freely up and down on the screw 56, thuscommensurately varying the angular pitch of the patient supportstructure 10.

The inboard end of the bracket arm 52 extends through the apertured gearbox 50 and is configured to form a clamp-like slot or channel 75 forreceiving an end of a patient support structure 10. The channel 75 has agenerally U-shaped configuration overall when viewed in cross section,however the vertical end wall portion includes a dovetail mortise 80 formating engagement with a corresponding tenon on the end of the supportstructure 10. It is foreseen that the inboard end of the bracket arm 52and the mating outboard end of the support structure 10 may includecorresponding vertically oriented apertures for receiving retainer pinsor the like. While the bracket arm 52 is depicted and described ashaving a dog-leg configuration and being of unitary construction, it isforeseen that other shapes may be employed and that the arm 52 may beconstructed in two or more sections, with the inner surface of theoutboard portion including an outstanding flange for connecting withfasteners to the inboard portion that includes the channel 75.

As shown in FIGS. 9-12, the angulation subassembly 27 is operated byactuating the DC motor 55 to engage the motor pulley (not shown) whichin turn rotates the pulley belt 63 that is reeved about the pulley 62that engages and rotates the lower end of the lead screw 56. It is alsoforeseen that any of a number of known systems of gears could beemployed to rotate the lead screw 56. Rotation of the lead screw 56pulls the lead nut 70 downwardly on its shaft along with the attachednut pivot block 51, closing the gap between the nut pivot block 51 andthe motor housing mount 53. As the lead nut 70 travels down the leadscrew 56, the resultant force on the outboard end of the bracket arm 52,which is trapped below the nut pivot block 51, causes the arm 52 topivot about the trunnions 73 riding on the block bearings 74. Theoutboard end of the arm 52 is tipped downwardly at the lead screw 56through the clearance slot 72 and continues to travel down the screw 56,shortening the distance between the bracket arm 52 and the motor housingmount 53. As the bracket arm 52 pivots, the inboard end of the armcontaining the channel 75 tips upwardly, varying the angular pitch ofthe table top 10 to an upraised position. Continued actuation of themotor will tip the table top 10 upwardly as shown in FIG. 11.

Reversal of the motor 55 serves to reverse the direction of rotation ofthe lead screw 56, which pushes the lead nut 70 upwardly on the screw56. The attached nut pivot block 51 follows the lead nut and urges theattached outboard end of the bracket arm 52 upwardly along the screw 56through the clearance slot 72, increasing the gap between the nut pivotblock 51 and the motor housing mount 53. As the bracket arm 52 pivots,the inboard end of the arm containing the channel 75 tips downwardly,commensurately varying the angular pitch of the patient supportstructure 10 to a lowered position. Continued actuation of the motorwill tip the table top 10 downwardly as shown in FIG. 12.

In the configuration depicted in FIGS. 11 and 12, each end of thepatient support structure 10 may be positioned to subtend an angle offrom about 0° (horizontal) to about +25° upward or −25° downward fromhorizontal. However, it is foreseen that, depending on the configurationof the gear box 50 and components of the angulation subassembly 27, thesupport structure may be positioned to subtend an angle of up to about+90° upwardly or −90° downwardly from horizontal, that is to say, froman approximately perpendicular upstanding or approximately perpendiculardependent position, with a full range of motion of the table top 10 ofup to about 180°.

As shown in FIGS. 8-10, the second patient support structure 10 a issupported by a bracket arm 52 a having a pair of sockets 58 on theoutboard end thereof for receiving the respective riser posts 48.Because the riser posts 48 are received in the slide channels 47 of therotatable block 33, both the patient support structure 10 and the secondpatient support structure 10 a are rotated by the action of the rotationsubassembly 26. However, the angular pitch of the second patient supportstructure 10 a is fixed by the registry of the riser posts 48 within thesockets 58, and will not be varied by the operation of the angulationsubassembly 27.

The distance between the patient support structure 10 and second patientsupport structure 10 a may be selectively increased or decreased by theoperation of the separation subassembly 28 in order to provide supportfor a patient during 180° rotation of the structures 10 and 10 a by therotation subassembly 26. The separation subassembly 28 is depicted inFIGS. 1-3 and 8-10 to include first and second pairs of elongate guidebars or rails 81 that adjustably interconnect the rotatable block 33 andgear box 50 at each end of the system 1. The guide rails 81 have agenerally triangular configuration in cross section and are installedwith the base of the triangle oriented toward the shorter side walls ofthe rotatable block 33 and gear box 50. The guide rails 81 are connectedto the shorter side walls of each rotatable block 33 by guide endbrackets 82, that are shaped to receive the guide rails 81. The shorterside walls of the gear box 50 each include a channel or bracket 83 thatmay be undercut, so that the side walls partially overlap and retain theangular sides of the guide rails 81 in sliding relation within thebracket (FIG. 8). The center portion of the gear box bracket 83 includesa slot for mounting linear bearings (not shown). The inner facingsurface of each guide rail 81 includes a normally vertical slot 84 formounting a linear bearing rail 86 (FIGS. 9, 10), upon which the linearbearings ride.

As best shown in FIG. 8, the floor of the gear box 50 is apertured toreceive a housing 85 containing a lead screw 90. The lead screw isconnected to a DC motor or other suitable actuator 91 within a motorhousing. The motor 91 is fixedly attached to the inside surface of theupper wall of the gear box 50. The lead screw 90 is threaded into a leadnut (not shown) that is fixedly attached to the floor of the gear box50.

The separation subassembly 28 is operated by actuating the motor by aswitch or similar device. The motor 91 rotates the lead screw 90 to pullthe lead nut and attached gear box 50 upwardly or downwardly on itsshaft, depending on the driving direction of the motor 91. The gear box50 travels upwardly or downwardly on the bearing rails 86 attached tothe guide rails 81, thus raising and lowering the attached patientsupport structure 10 with respect to the rotatable block 33. Where asecond patient support structure 10 a is attached by means of riserposts 48 to the rotatable block 33, the upward and downward travel ofthe gear box 50 serves to shorten and lengthen the distance between thetwo patient support structures 10 and 10 a.

The horizontal support assemblies 5 and 6 support a table top 10 andoptional top 10 a or other suitable patient support structure such as,for example, open frames, slings or bolsters or combinations thereof. Atop 10 suitable for surgery is depicted in FIG. 14 to include a patientbody support board 92 coupled with first and second patient leg supportboards 93 and 94 by a pair of lockable universal or polyaxial jointassemblies 95 and a dependent pillow support structure 96. FIGS. 8 and 9depict an optional second support board 92 a of open frame construction.

The body board 92 is of unitary construction and is sized to support thehead and body of a patient except for the legs. The body board 92includes an elongate rectangular outboard bracket-engaging section 100having a dovetail tenon 101 sized for snug sliding reception within thedovetail mortise 80 in the bracket arm channel 75 (FIG. 12). Thebracket-engaging section 100 is joined to a generally rectangular centersection 102 having four slightly relieved corners (FIG. 1). An elongateperineal section or leg 103 projects from the inboard end of the centersection 102 and an upright perineal post 104 is removably mountedadjacent the inboard end of the perineal leg 103. The perineal post 104is preferably constructed of a radiolucent material to permit imaging.The post 104 may have a generally cylindrical configuration as depicted,or it may be constructed in any other suitable shape for supportingengagement with the perineal region of a patient.

As shown in FIG. 5, the body board center section 102 may serve as astage for attachment of certain optional and removable accessories. Forexample, a pivoting padded arm board having strap-type restraints 106may be employed for lateral positioning of the patient's arm. A crossarm support structure 110 including an elevated arm board 111 may beemployed for raised, spaced positioning of the patient's arm withrespect to the body.

The first and second patient leg boards 93 and 94 are rotatably attachedto the body board center section 102 in spaced relation to the perinealleg 103 by first and second polyaxial joint assemblies 95. The legboards 93 and 94 each have a generally elongate rectangularconfiguration with relieved corners. The outboard ends each include abracket-engaging section 112 having a dovetail tenon 113 for receptionwithin the dovetail mortise 80 in the bracket arm channel 75. Theinboard end of the foot end bracket arm 52 and each of thebracket-engaging sections 112 are vertically apertured to receive a pairof spaced removable pins 114 for securing the leg boards 93 and 94 inplace (FIG. 1).

The body board 92 and leg boards 93 and 94 are constructed of aradiolucent material to permit patient imaging during use. Althoughdepicted in FIGS. 1-5 as being of equal length, those skilled in the artwill appreciate that the body board 92 may be constructed to havegreater length than the leg boards 93 and 94 or vice versa to enablepositioning of a patient so that articulation of the leg boards 93 and94 will occur adjacent the superior aspect of the iliac crest in orderto facilitate disarticulation of the hip and hyperextension of thelumbar spine as shown in FIG. 6. In addition, the board modules 92, 93and 94 may be selectively replaced with other modules having differentlengths or construction details, such as open frames, slings orbolsters.

FIGS. 13-17 show details of the polyaxial joint assemblies 95 thatinterconnect the body board 92 with the leg boards 93 and 94 to enableadjustment of the angular pitch in nearly all directions. The joint 95includes a housing 115 having a generally spherical interior socket 116that receives a generally spherical ball member 120. The outer rear wallof each housing 115 includes an orthogonally projecting shaft 121 thatis installed within a corresponding bore in the inboard margin of thebody board 92. The ball 120 is mounted on a shaft 122 that is installedwithin a corresponding bore in the inboard margin of a leg board 93 or94. The housing 115, which may be constructed of radiolucent carbonfiber or other suitable material, includes a pair of spaced threadedapertures 123 for receiving a pair of pads or set screws 124, each ofwhich has a correspondingly threaded stem and is equipped on theoutboard end with a handle or finger knob 125. The apertures 123 arepositioned so that the installed set screws 124 will subtend an angle ofabout 45° from an axis B defined by the housing shaft 121 as shown inFIG. 17. The stem of each set screw 124 terminates in an engagement tip130 that is arcuately configured in a generally concave conical shapefor mating engagement with the spherical surface of the ball 120 forcooperatively securing the ball against the inner surface of the socket116 (FIGS. 13 and 14). While a ball and socket type joint assembly hasbeen depicted and described herein, those skilled in the art willappreciate that any lockable universal joint, such as, for example, alockable gimbal joint may also be employed to enable polyaxial rotationof the leg boards 93 and 94.

The intermediate support structure 96 shown in FIGS. 1 and 3 to dependbetween the outboard ends of the leg boards 92 and 93 with the inboardend of the body board 92. The structure 96 is designed to convert from apillow support to a brace when it is positioned as shown in FIGS. 4 and5. The structure 96 includes a pivotable first support element 131,telescoping second and third support elements 132 and 133 and a pair ofdependent spaced wire supports 134. The elements 131, 132, 133 and wiresupports 134 depend from the patient support top 10 in end-to-endrelation to form a shelf which may be used for supporting an optionalpillow (not shown) that is configured to extend upwardly to fill thespace between the leg boards 93 and 94.

The first element 131 is generally rectangular and planar, and isequipped at each end with a hinge 135 or 135 a (FIG. 3). Hinge 135pivotally connects one end to the lower surface of the body board 92.Hinge 135 a pivotally connects the opposite end to the second supportelement 132. The hinges 135 and 135 a enable pivotal movement of theelement 131 from the dependent position shown in FIG. 1 to a positionparallel and adjacent the lower surface of the body board 92 shown inFIG. 4.

The generally planar rectangular second element 132 is joined at one endto the first element 131 in a generally perpendicular orientation. Theopposite end of the second support element 132 is slidingly andtelescopically received within a hollow end of the third support element133. The hollow end of the third element 133 also includes conventionalrack and pinion gear structure (not shown) similar to that within thecrossbar 13 to permit locking telescoping adjustment of the length ofthe two coupled elements when in the upright positions shown in FIGS.4-6. The third support element 133 is generally planar and rectangularexcept for a notch 140 at the outboard end (FIG. 1). The notch 140 issized to receive the first rail 14 of the crossbar 13 when the thirdsupport element 133 is in an upright position shown in FIGS. 4-6.

The wire supports 134 comprise two spaced sets of articulated wiresections 134 a, 134 b, and 134 c, each of which sets depends from arespective foot board 93 or 94. It is foreseen that a stabilizingcrossbar may also be included at the junction of the first and secondsections 134 a and 134 b or other suitable location. The lower sections134 b and 134 c are pivotable upwardly from the position shown in FIG. 4to form a generally triangular releasable loop foot (FIG. 3) that issized to receive an outboard end corner of each of the leg boards 93 and94.

In order to achieve unrestricted positioning of a patient's legs, theleg boards 93 and 94 can be disengaged from the angulation subassembly27 and raised, dropped down or rotated nearly 360° in all directions(FIGS. 5 and 6). As shown in FIGS. 3-6, it is desirable to firstdisengage the support structure 96 from its pillow-supporting positionto form an upright brace for providing additional support for the bodyboard 92. This is accomplished by unfolding the loop foot portion ofsupport bracket 134 so that it disengages the outboard corners of thepillow shelf element 133. The top ends of the wire supports 134 can thenbe disengaged from the foot boards 93 and 94 and removed for storage.The first support element 131 is rotated about the hinge 135 to theposition shown in FIG. 4. As the first support element 131 is rotatedthe second and third support elements rotate downwardly and about thehinge 135 a. The rack and pinion gear system is actuated by the motor141 to urge the second support element 132 outwardly from its telescopedposition within the third support element 33, thereby elongating thesupport until the slot 140 engages the crossbar rail 14 in straddlingrelation. It is foreseen that an elastomeric gasket 139 may be providedbetween the now upstanding end of the second support element and thelower surface of the body board 92 to cushion against any flexing ortilting of the body board 92 which may occur when the foot boards arereleased from the angulation subassembly 27. Similarly, the floorengaging corners of the support element 133 may also be equipped withelastomeric feet to facilitate snugging of the brace 96 against the bodyboard 92 and to prevent any slippage of the support element 133 alongthe surface of the floor.

Once the pillow support structure 96 has been converted to an uprightbrace as shown in FIG. 4, one or more of the leg boards 93 and 94 may bereleased from the bracket arm channel 75. One or more of the pins 114 isreleased and the bracket engaging leg board tenon 113 is slidinglydisengaged from the bracket mortise 80 (FIGS. 1 and 5). If both of theleg boards 93 and 94 are released, the floorlock foot lever 25 and thetelescoping cross bar rails 14 and 15 may be completely disengaged,leaving the inboard end of the rail 14 supported by the wheel 24 (FIG.6). This frees the disengaged second horizontal support assembly 6 andits attached upright support column 4, which may be wheeled out of theway. In this manner, access by the surgical team and its equipment tothe midsection and lower limbs of the patient is greatly enhanced.

As shown in FIG. 5, an optional leg spar assembly 142 may be attached tothe free end of each leg board 92 and 93 for mounting a traction boot143 or cable (not shown). The leg boards 93 and 94 may each be rotatedabout one of the ball joints 95, by rotating the finger knob 125 counterclockwise to release the ball 120 within the socket 116. For example, asshown in FIG. 6, the right leg board 94 may be dropped down and tiltedlaterally or medially with respect to a longitudinal axis todisarticulate the hip of the patient. When the desired angularorientation or pitch of the patient's leg is achieved, the respectivefinger knob 125 is rotated clockwise to engage the ball against thesurface of the socket 116 and secure the leg board 92 or 93 in place.

The system 1 of the invention has been described as actuated by a seriesof electric motors 23 (vertical translation of support columns 3 and 4and lateral translation of rack and pinion 21 and 22), 34 (rotationsubassembly 26), 55 (angulation subassembly 27), 91(vertical translationof linear guide rail subassembly), and 141 (intermediate supportstructure 96). Cooperatively these motors form a coordinated drivesystem to raise, lower, tilt and rotate the patient support structuresand to disengage the second support column 4 from the system 1.Actuation of the motors is coordinated by the controller 29, includingcomputer software which may be part of an integrated guidance systemthat coordinates and controls other devices such as a robotic surgicalarm, imaging, monitoring and/or heated or cooled gas and fluid delivery,as well as temperature and/or pressure point management devices. Thesoftware may include preset routines for positioning components inpreselected positions. In addition, the software may include thecapability of fine tuning any aspect of the configuration of the system1. For example, as the motor 23 is actuated to lower the head and footend support columns 3 and 4, the motor 91 may also be selectivelyactuated to lower the body board 92 with respect to the rotatable block33 while each of the motors 55 are also actuated to tip the body board92 upwardly and the opposed leg boards 93 and 94 downwardly inaccordance with the new angle subtended by the support columns 3 and 4to a position in which the hips of the patient are above both the headand the feet. It is also foreseen that in lieu of the system ofcoordinated electric motors described herein, a hydraulic or pneumaticsystem could be employed.

In use, the horizontal support assemblies 5 and 6 may be positioned in ahorizontal orientation and at a convenient height to facilitate transferof a patient onto the support surface 10. The patient is positioned in agenerally supine position with the head, torso and lower body except forthe legs on the body board 92 outboard of the perineal post 104, andwith one leg on each of the leg boards 93 and 94. Arm boards 105 and 111may be attached to the body board 92 as necessary, and the patient'sarms arranged thereon and restrained using the straps 106.

The patient may be tilted to a Trendelenburg position (as shown in FIG.23), or a reverse Trendelenburg position in which the head is raisedabove the feet, by actuating the motors 23 and 55 to selectively lower aselected support column 3 or 4 and adjust the angulation of the bodyboard 92 and leg boards 93 and 94. Once suitably restrained, the patientmay be rotated or rolled from the supine position to a clockwise orcounter clockwise laterally tilted position by actuating the motors 34to rotate the blocks 33.

One or more of the leg boards 92 and 93 may be disengaged and thepatient's legs positioned for example, for hip surgery, by convertingthe intermediate support structure 96 from its pillow-supportingconfiguration to a central support column as shown in FIG. 4 bydisengaging the wire supports 134, rotating the first support element131 about the hinges 135 to its horizontal position and actuating themotor 141 to extend the support elements 132 and 133 to engage the rail14. The wire supports 134 are removed and the pins 114 are removed fromthe bracket arm 52. The bracket engaging section 112 of each of the legboards 93 and 94 is slid out of the channel 75 by laterally rolling orrotating the respective leg board about the respective polyaxial balljoint 95. This is accomplished by manually turning the finger knob 125through the sterile drapes to disengage the set screw 124 from the ball120 and permit free rotation of the ball within the socket 116.

The foot end separation assembly motor 91 may be actuated to raise thegear box 50 to its highest position on the guide rails 81 and the motor23 may be actuated to lower the foot end support column 4 to its lowestposition. The foot end floorlock foot lever 25 is next disengaged tofree the foot end support column 4, while the head end support column 4remains locked down. The motor 23 is actuated to urge the rack andpinion 21 and 22 to commence withdrawal of the rail 15 from itstelescoped position within the rail 14 and thereby lengthen the crossbar13 to its fully extended position. The rack and pinion locking assembly20 is then released either manually or by means of a switch so that theentire second upright support column 4 with its horizontal supportassembly 6 and attached rail 15 may be wheeled out of the way to providethe surgical team and equipment with free access to the pelvis as wellas to the hip joints and legs of the patient from both a medial andlateral approach.

Once the leg boards 93 and 94 have been rotated laterally, away from thelongitudinal axis of the system 1, they may be positioned as shown inFIG. 6, with the outboard ends tilted upwardly or downwardly and angledlaterally or medially. The leg boards 93 and 94 are secured in place inthe selected angular orientation by manually tightening each of thefinger knobs 125 through the sterile drapes until the engagement tips130 lock the ball 120 against the inner surface of its socket 116. Legspar assemblies 142 may be installed on the leg boards 93 and/or 94 andthe patient's feet may be fitted with traction boots 143.

A second embodiment of the patient support system of the invention isgenerally designated by the reference numeral 201 and is depicted inFIGS. 18-27 to include a base 202, support columns 203 and 204 andhorizontal support assemblies 205 and 206 including rotationsubassemblies 226, angulation subassemblies 227 and linear guide rail orseparation subassemblies 228 substantially as previously described. Thepatient support structure 210 includes a pair of body boards 292 and293, depicted as surgical tops and open frames (FIG. 18), although aspreviously discussed, other suitable structures such as slings, bolstersor a combination thereof may be employed. The boards 292 and 293 eachinclude bracket engaging sections 300 that are received within channels275 in brackets 283 attached to gear boxes 250. The inboard ends of thebody boards 292 and 293 are free so that they may be independentlyraised and lowered by the support columns 203 and 204 (FIG. 26). Thedistance between the inboard ends may be increased or decreased byactuation of a rack and pinion in the crossbar first section 214 totelescopically receive a portion of the second crossbar section 215,shortening the horizontal length of the crossbar 213 to achieve theoverlapping positioning of the body boards 292 and 293 depicted in FIG.25. The body boards 292 and 293 need not be uniform in size and may varyin length and thickness (in which case correspondingly sized brackets252 are employed). In particular the foot end board may be longer thanthe head or torso board, in which case the angulation of the boards whenthe ends are proximate would occur at approximately the waist of thepatient. As shown in FIG. 18, a frame type patient support 210 may beemployed in conjunction with a body board type of support to support apatient, or a pair of frame type patient supports may be employed inlieu of body boards. It is foreseen that the free ends of the bodyboards 292 and 293 may be spaced substantially apart and a third bodyboard (not shown) may be interconnected by means of additional brackets252 on the free ends of the boards 292 and 293 in order to provide asubstantially elongated patient support surface 210. It is also foreseenthat the boards 292 and 293 may be brought into contact with each otherin stacked relation, for example for use with children or in small roomsin order to reduce the overall length of the system 201. Since such anarrangement necessarily provides a double thickness patient supportstructure, the resultant structure has a greater load bearing capacity.The angulation of each of the body boards 292 and 293 may also beindividually adjusted by the angulation subassembly 227 as shown inFIGS. 23, 24 and 27 and the adjustment may be coordinated to achievecomplementary angulation for positioning of a patient, for example withthe inboard ends of the body boards 292 and 293 upraised as shown inFIG. 24.

As shown in FIGS. 18-21 and 25, the system 201 is designed to include anoptional and removable second pair of patient support structures 210 aattached by brackets 252 coupled with riser posts 248. The supportstructures 210 a are depicted in FIGS. 8 and 18 as first and secondgenerally rectangular open frames 292 a and 293 a and as surgical topsin FIGS. 19-21 and 25. Those skilled in the art will appreciate that thepatient support structures 210 and 210 a may comprise conventionalsurgical table tops and open frames as described or any other structurecapable of supporting a patient, whether directly or in association withpads, slings, cables, brackets, pins or in any other suitable manner.Any of the board modules 292, 292 a, 293 and 293 a may also be removedand replaced by modules of alternate construction during the course of amedical procedure as may be desirable. The body boards/frames 292 a and293 a include bracket engaging sections 300 a that are received withinchannels 275 in corresponding brackets 283 a. The outboard portion ofeach bracket 283 a includes a pair of sockets 258 for receiving a pairof riser posts 248. The riser posts 248 include a series of verticalapertures 249 for receiving pins 249 a for holding the riser posts 248in place at a preselected height or distance above the rotatable blocks233.

The body boards and/or frames 292 and 292 a also be equipped withoptional and removable accessories such as a cross arm support 310 andarm board 311 and the body boards and/or frames 293 and 293 a may alsobe equipped with accessories such as leg spar assemblies 342 as shown inFIG. 24 or other support assemblies such as the kneeler assembly 317shown in FIG. 27

In use, the second pair of support structures 210 a are installed bysliding the sockets 258 over the corresponding riser posts 248 andfastening in place with pins 249 a through the apertures 249 as shown inFIG. 18. The rotation subassembly 226 is actuated to operate aspreviously described for rotating the blocks 233 along with the attachedframes 292 a and 293 a and the gear boxes 250 along with the attachedbody boards 292 and 293 about the longitudinal axis of the system 201into the 180° position shown in FIG. 19.

The separation subassembly 228 is actuated to operate in the mannerpreviously described to urge the gear boxes 250 along with the attachedbody boards 292 and 293 along the guide bars 281 and into the upraisedposition shown in FIG. 19 to provide ample space for transfer andpositioning of a patient. The overall height of the system 201 may beadjusted for convenient patient transfer by actuating the telescopingaction of the support columns 203 and 204. The upright support columns203 and 204 raise and lower the patient support structures 210 and 210 ain tandem, and cooperate with the separation subassembly 228 to set thepatient support structures 210 and 210 a at a preselected height withrespect to the floor and a preselected separating distance with respectto each other.

A patient is next transferred onto the support boards 292 a and 293 aand a protective guard 294 is positioned over the face and restraintstraps 295 positioned at strategic points along the patient's body andsnugged against the body boards 292 a and 293 a. The separationsubassembly 228 is actuated to urge the gear boxes 250 closer to therotatable blocks 233, decreasing the distance or separation between thepatient support boards in the position shown in FIG. 20.

The rotation subassembly 226 is next actuated to rotate the blocks 233along with the body boards 292 a and 293 a and the attached gear boxes250 and attached body boards 292 and 293 with the patient in thegenerally supine position shown in FIG. 21 to the generally proneposition shown in FIG. 22. The rotation subassembly 226 cooperates withthe angulation subassembly 227, the support columns 203 and 204 and theseparation subassembly 228 to enable rotation of the patient supportstructures 210 and 210 a about a longitudinal axis, that is preselectedaccording to the respective selected heights of the support columns 203and 204 and the respective selected separation spacing of the patientsupports 292 and 293 and 292 a and 293 a by the guide rails 281. Asindicated by the arrows, the system 201 may be rotated 360° in eitherclockwise or counterclockwise direction.

Once the patient has been repositioned, the second patient supportstructure 210 a, including the boards 292 a and 293 a and associatedbrackets 252 and riser posts 248 may be removed to provide full accessto the surgical field. The linear guide rail subassemblies 228 may beactuated to raise the gear boxes 250 and connected body boards 292 and293 up to a position adjacent the blocks 233.

As shown in FIG. 23, the angulation subassemblies 227 cooperate with thesupport columns 203 and 204 to permit independent adjustment of theheight of the support columns, so that the body boards 292 and 293 maybe set at an angle, with the patient's head above or below the feet.Cooperation of the angulation subassemblies 227 with the support columns203 and 204 and with the telescoping crossbar 213 enables positioning ofthe patient with the head and torso horizontal in an upper plane andwith the lower legs horizontal in a lower plane as shown in FIG. 26 andcoordinated upward tipping of the patient with the head and torso andlower legs maintained in parallel angled planes as shown in FIG. 27.

It is to be understood that while certain forms of the present inventionhave been illustrated and described herein, it is not to be limited tothe specific forms or arrangement of parts described and shown.

What is claimed is:
 1. A surgical table comprising: an elongate basecomprising a first foot, a second foot opposite the first foot, and alength-adjustable cross-bar interconnecting the first foot and thesecond foot; a first column comprising a first bottom end and a firsttop end opposite the first bottom end, the first column surmounted onthe first foot at the first bottom end, the first column beingvertically adjustable between the first top end and the first bottomend; a second column comprising a second bottom end and a second top endopposite the second bottom end, the second column surmounted on thesecond foot at the second bottom end, the second column being verticallyadjustable between the second top end and the second bottom end; a firstsupport assembly coupled at or near the first top end of the firstcolumn; a second support assembly coupled at or near the second top endof the second column; and a patient support structure comprising a firstend, a second end opposite the first end, and a hinge intermediate thefirst and second ends, the first end operably engaged with the firstsupport assembly, the second end operably engaged with the secondsupport assembly, wherein the first end of the patient support structureis configured to vertically translate towards the first foot while thefirst column remains in a fixed vertical position during pivoting of thepatient support structure at the hinge.
 2. The surgical table of claim1, wherein, in the fixed vertical position, a distance between the firstbottom end and the first top end does not change.
 3. The surgical tableof claim 1, wherein, when the first end of the patient support structurevertically translates, the first end is guided by the first supportassembly.
 4. The surgical table of claim 1, wherein, during pivoting ofthe patient support structure at the hinge, the first end of the patientsupport structure is configured to move closer to the second column. 5.The surgical table of claim 4, wherein the first column and the secondcolumn move closer together via telescoping movement of the cross-barwhich causes the first end of the patient support structure to movecloser to the second column.
 6. The surgical table of claim 1, whereinthe first end of the patient support structure vertically translatesalong a linear path relative to the first column.
 7. The surgical tableof claim 1, wherein the first support assembly comprises a rotationsubassembly and a separation subassembly, the rotation assemblypositioned at or near the first top end of the first column andconfigured to rotate the patient support structure about a rotationaxis, the separation subassembly comprising a pair of guide rails spacedapart from each other and configured to raise and lower the first end ofthe patient support structure along the pair of guide rails.
 8. Thesurgical table of claim 7, wherein the pair of guide rails extendsdownward from the first rotation subassembly.
 9. The surgical table ofclaim 8, wherein the pair of guide rails is parallel with the firstcolumn.
 10. The surgical table of claim 7, wherein the rotation axis ispositioned above the first end of the patient support structure.
 11. Asurgical table for supporting a patient during a surgical procedure, thesurgical table comprising: a patient support structure for supportingthe patient and comprising a first end, a second end opposite the firstend, and a hinge intermediate the first and second ends; an elongatebase comprising a first foot, a second foot opposite the first foot, anda cross-bar interconnecting the first foot and the second foot; a firstcolumn comprising a first bottom end and a first top end opposite thefirst bottom end, the first column surmounted on the first foot at thefirst bottom end, the first column being vertically adjustable betweenthe first top end and the first bottom end; a second column comprising asecond bottom end and a second top end opposite the second bottom end,the second column surmounted on the second foot at the second bottomend, the second column being vertically adjustable between the secondtop end and the second bottom end; a first support assembly coupled ator near the first top end of the first column, the first supportassembly comprising a rotation subassembly and a separation subassembly,the rotation assembly configured to rotate the patient support structureabout a rotation axis, the separation subassembly positioned below therotation subassembly and comprising a pair of guide rails spaced apartfrom each other, the separation subassembly operably engaged with thefirst end of the patient support structure and configured to guide thefirst end of the patient support structure along the pair of guide railsso as to move the first end closer to or further from the rotationsubassembly; and a second support assembly coupled at or near the secondtop end of the second column, the second end of the patient supportstructure operably coupled with the second support assembly.
 12. Thesurgical table of claim 11, wherein the rotation axis is positionedabove the first end of the patient support structure.
 13. The surgicaltable of claim 11, wherein, during pivoting of the patient supportstructure at the hinge, the first end of the patient support structureis configured to vertically translate on the pair of guide rails towardsthe first foot while the first column remains in a fixed verticalposition.
 14. The surgical table of claim 13, wherein, in the fixedvertical position, a distance between the first bottom end and the firsttop end does not change.
 15. The surgical table of claim 13, wherein,during pivoting of the patient support structure at the hinge, the firstend of the patient support structure is configured to move closer to thesecond column.
 16. The surgical table of claim 15, wherein the firstcolumn and the second column move closer together via telescopingmovement of the cross-bar which causes the first end of the patientsupport structure to move closer to the second column.
 17. An apparatusfor supporting a patient during a medical procedure, the apparatuscomprising: a base comprising a first foot, a second foot opposite thefirst foot, and a cross-bar interconnecting the first foot and thesecond foot; a first column surmounted on the first foot, the firstcolumn being vertically adjustable relative to the first foot; a secondcolumn opposite the first column, the second column surmounted on thesecond foot and being vertically adjustable relative to the second foot;a patient support structure coupled to and between the first and secondcolumns, the patient support structure comprising a first section havinga first outer end, a second section having a second outer end, and anarticulation inwardly connecting the first and section sections, thearticulation having an axis of articulation about which the first andsecond sections are configured to articulate, wherein, the second outerend of the patient support structure is configured to follow an arcuatepath of motion with respect to the second column when the first andsecond sections articulates at the articulation.
 18. The apparatus ofclaim 17, wherein the first outer end of the patient support structureis operably coupled to the first column, and the second outer end of thepatient support structure is operably coupled to the second column. 19.The apparatus of claim 17, wherein the cross-bar is configured to extendand retract so as to move the first and second columns further apart andcloser together, respectively.
 20. The apparatus of claim 17, furthercomprising a first separation assembly configured to raise and lower thefirst outer end of the patient support structure relative to the firstcolumn.